1. Field of the Invention
The present invention generally relates to the art of gas/liquid separation for recovering sample and/or solvent in solution. Particularly, it is concerned with a gas/liquid separator constructed by combining a heat-exchanging condensor of high cooling and condensing efficiency with an adiabatic resorvoir for the condensed liquid of an excellent trapping efficiency. Said separator also has a sufficient safety and convenience for permitting an operator an easy handling in, for instance, a chemical laboratory without poluting its environment by maintaining possible re-evaporation minimum.
2. Description of the Prior Art
Hitherto, vapor of solvent generated from a rotary flask or test-tube evaporating/condensing apparatus has, in general, been being cooled by employing a coolant-circulating coiled condensor. Gas phase which cannot be liquified from the vapor during its travel through the condensor has however been sucked by an aspirator and simply expelled from the laboratory through, for example, a draft chamber.
The cooling tube of the known coolant-circulating coiled condensor has however an insufficient cooling efficency. Should a related apparatus or apparata of some complementary nature be employed, its solvent distilling efficiency cannot be made sufficiently high. Thus, a hazard of intoxication for operators or a polution of the environment cannot be avoided in handling a solution which contains a low boiling-point solvent or a noxious/inflammable solvent.
In particular, in the case of treating a sample labeled with radio-isotope, an aspirator of sink-discharge type cannot be used and thus, the use of one of circulating type in a closed system is considered to be compulsory. In general, if the cooling tube does not have a sufficient solvent liquefying/recovering efficency, any of the low boiling point solvents is inevitably mixed with the water running through the aspirator to suck the vapor, inviting a conspicuous decrease in the degree of vacuum (vacuum level) to be attained. In a closed system in particular, the low boiling-point solvent is being accumulated little by little in the circulating water during the operation. Even if only scanty amount of the solvent is being dissolved in the water at a time, the evacuating ability of aspirator is remarkably lowered in the end. In order to effectively overcome the mentioned drawbacks and to improve the vapor cooling and condensing ability of the cooling tube, there has heretofore been proposed various gas/liquid separating apparata, some of which are combined with any means for efficiently trapping the condensed solvent.
One of these proposal has been disclosed in Japanese Laid-Open Utility Model Application (Jikkaisyo) 62-156,302 by the present inventors and illustrated here in FIG. 6 of the attached drawings. The disclosure relates to a gas/liquid separator characterized in a combination of a heat-exchanging condensor 210 of double tube type wherein a lower end of an inner tube 212, a descending path for mixture of vapor with condensed liquid introduced from a vapor inlet 216 at its top, is extended downward and terminated at a vicinity of a lower part of an outer tube 214. The heat-exchanging condensor 210 communicates with said outer tube 214 which has an outlet 218 for evacuation at its top and an outlet tube 220 for the condensed liquid at its lower end, a means for cooling said condensor from outside by, for instance, with a freezing mixture held in a container 224, and an adiabatic reservoir 222 for the condensed liquid having an opening 226 capable of detachably fitting with the outlet tube 220 of said condensor by, for instance, a ball-joint 228. Said reservoir 222 also has, at its shoulder, an outlet 232 for the liquid, connected with a guide tube 230 and a cock 234.
A great improvement in the solvent trapping efficiency has been made by embodying this proposal, though, the temperature of the solvent recovered from the embodied apparatus cannot be made sufficiently low. Thus, an escape of raw vapor from the apparatus cannot be avoided and an efficient separation of solidifying solvent such as water, benzene, glacial acetic acid and the like is still difficult.
Another proposal disclosed in Jikkaihei 1-120,902 (Laid-open print of Japanese Utility Model Application, Jitsugansho 63-17,715) by the present inventors has been made also on a gas/liquid separator of a combination of a heat-exchanging condensor 10' with an adiabatic reservoir 50' for the condensed liquid, illustrated here in FIGS. 7 and 8, respectively. In the disclosed apparatus, the heat-exchanging condensor 10' is composed of a container 30 of coolant formed integrally with while centering about a vertical pipe structure 12. The vertical pipe structure 12 has a top opening 16 for communicating with an evacuating means or a vapor generating means through a connector 20 provided with a ball-joint 18 and a bottom opening 22. The vertical pipe structure 12 permits inflow of vapor and outflow of condensed liquid. In the vertical structure 12 between the top opening 16 and the bottom opening 22, ascending or descending flow of the vapor and descending flow of the condensed liquid pass through. The apparatus further has an inner pipe conduit 34 which is substantially concentric with and runs in substantially parallel with said vertical pipe structure 12 between an upper outlet 36 and a lower inlet 38, through which the space inside said inner pipe conduit 34 is communicating with a space 32 formed between the inner side wall of said container 30 and the outer side wall of said vertical pipe structure 12 for circulating the coolant. Said adiabatic reservoir 50' has, at its top 52, an opening (a ball-joint 54) for detachably fitting with said bottom opening 22 of said vertical pipe structure 12. Said adiabatic reservoir 50' is formed integrally with a head part 56, being just beneath said top part 52, a shoulder 64 and a body 66 in said order. Said head part 56 accommodates a dew-drop type centering device 58 of a pointed lower end 59, having vents 60 for escaping vapor. Said shoulder 64 is provided with a first opening 68 with a ball-joint 74 and a second, communicating, opening 70 with a guide tube 78' which reaches the inner bottom of the reservoir 50'.
Any one of these disclosed apparata is presupposing the use of a freezing mixture, such as dry ice/acetone, as its active coolant. The use of the freezing mixture capable of producing an extremely large temperature gradient with respect to the dew point of the solvent vapor to be treated is intended so that the mixture could act on the solvent vapor through the wall, which separates the most effectively the spaces inside and outside the vertical pipe structure, which is accommodated in said container.
The operation of these apparata is however troublesome in a sense, because the charged dry ice is being consumed with the progress of the heat-exchange and must be replenished constantly if one wishes to maintain the temperature of the freezing mixture to that is intended.
In the apparatus disclosed in Jikkaisyo 62-156,303 by the present inventor and illustrated in FIG. 9 here, a heat-absorbing rod means (freezing rod) 518 is connected to a split type refrigerator 530, through a coolant path 516 covered with an heat-insulator coating 520. The rod is concentrically accommodated in a core tube of a heat-exchanging condensor 510, in order to obviate the mentioned trouble. An intact pass-through of the raw vapor cannot, however, be avoided because only central portion of the travelling vapor flow actually contacts with the freezing rod to be cooled. An adiabatic reservoir 522 similar to that aforementioned is also employed. In order to improve the cooling ability of the freezer rod, fins may be provided a round the rod. The cooling efficiency might even be lowered however, by any material stuck to the fins, and species of the solvent vapor which can be treated might sometimes be limited because of the attendant problems of possible corrosion and polution of the fins.
What is needed is a gas/liquid separation system which can be inexpensively manufactured and yet performs the separation efficiently. Sufficiently rugged construction and simple operation for running the system are also essential for the apparatus which permits heavy and abusive use by any person who is not an expert in a laboratories.
Other objects of the present invention and the attendant advantages thereof will be made apparent to those skilled in the art by reading the following detailed description.